Ships-of-the-line. Eighteenth century Mendean

The ship-of-the-line was the most powerful warship of the
age of sail. A country’s naval power was measured by the
number of ships-of-the-line it boasted; these ships had two
or even three rows of guns on each side, and could singlehandedly
determine the course of great sea battles.
Initially, many ships-of-the-line in the Spanish navy were
built in Basque shipyards, although this work was later moved
to other areas. Many Basque carpenters and workmen
specialising in the construction of ships-of-the-line were hired
by the royal shipyards elsewhere on the Iberian peninsula
and in the territories abroad.
Initially the ship-of-the-line, which was larger than the frigate,
proved top-heavy and unstable because of the weight of
its guns. Antonio de Gaztañeta from Mutriku developed an
innovative system for designing the underwater hull which
notably increased the stability of the ship without reducing
its speed. This method, based on a system of graphs, also
ma-de it possible to predetermine exactly the shape of the
fore and aft parts of the hull, which had previously depended
on improvisation and the good workmanship of each builder.